JP2009085322A - Electromagnetic actuator - Google Patents

Abstract

An object of the present invention is to suppress the magnetic resistance of a housing formed integrally with a movable core and reduce the overall configuration.
A valve body 18 and a housing 14, a fixed core portion 54 integrally formed with the housing 14 by a carbon steel material, a solenoid portion 12 having a movable core 40 sucked by the fixed core portion 54, and a radius. An annular flange portion 68 protruding outward, and the fixed core portion 54, the housing 14, the annular flange portion 68, and the movable core 40 constitute a magnetic circuit, and the housing 14 includes the fixed core. After being integrally formed including the portion 54, an annealing process is performed in which the part 54 is heated to a predetermined temperature and then gradually cooled.
[Selection] Figure 1

Description

  The present invention relates to an electromagnetic actuator capable of displacing a valve shaft integrally with the movable core by attracting the movable core to a fixed core portion by an electromagnetic force generated under an excitation action of a solenoid portion.

  With regard to this type of electromagnetic device, the applicant of the present application has proposed an electromagnetic valve related to a three-way valve that switches the flow of pressure fluid flowing through a fluid passage (see Patent Document 1).

  In the electromagnetic valve disclosed in Patent Document 1, a solenoid portion is housed in a housing, the first on-off valve is disposed in a direction away from the solenoid portion, and closer to the solenoid portion than the first on-off valve. A valve seat structure is employed in which a second on-off valve is disposed in the same direction and the seat diameter of the second valve seal of the second on-off valve is set smaller than the seat diameter of the first valve seat of the first on-off valve. ing.

In the electromagnetic valve disclosed in Patent Document 1, the seat diameter of the second valve seal of the second on-off valve is set smaller than the seat diameter of the first valve seat of the first on-off valve. Since the valve opening force due to the fluid pressure with respect to the on-off valve can be reduced, the spring force of the spring provided in the solenoid part can be weakened, and the solenoid part can be miniaturized.
Japanese Patent Laid-Open No. 9-280391 (paragraphs 0015 to 0016, FIG. 1)

  The present invention has been made in connection with the above proposal, and provides an electromagnetic actuator capable of suppressing the magnetic resistance of a housing integrally formed with a movable core portion and reducing the overall configuration. Objective.

  To achieve the above object, the present invention provides a valve body including a valve body and a housing having an inlet port and an outlet port through which a pressure fluid flows, and a coil disposed inside the housing and wound around a coil bobbin. And a solenoid part having a fixed core part integrally formed with the housing by a carbon steel material, and a movable core formed with a nonmagnetic layer on the outer surface and attracted to the fixed core part under energizing action on the coil; A valve shaft coupled to the movable core and displaced integrally with the movable core; and a valve body that switches between a communication state and a non-communication state of the inlet port and the outlet port under the displacement action of the valve shaft; An annular flange portion provided on the outer peripheral surface of the valve body and projecting radially outward, the fixed core portion, the housing The annular flange portion and the movable core form a magnetic circuit, and the housing is integrally molded including the fixed core portion, and then annealed to gradually cool after being heated to a predetermined temperature. It is characterized by being given.

  According to the present invention, when the housing is integrally formed with the carbon steel material including the fixed core portion, distortion occurs at the joint portion between the fixed core portion and the housing constituting a part of the magnetic circuit, thereby increasing the magnetic resistance. However, by performing an annealing process that gradually cools after heating to a predetermined temperature, the strain can be removed and the magnetic resistance can be suppressed.

  That is, the inventors of the present invention actuate the solenoid part (movable) when the solenoid part is manufactured by assembling the coil and the movable core with respect to the housing integrally formed of the carbon steel material including the fixed core part. The phenomenon that the minimum voltage (current) for attracting the core to the fixed core part and turning the solenoid part on is higher than that of the conventional product occurs. This cause is CAE (Computer Aided Engineering). As a result of analysis, the stress concentrates on the joint (boundary part) between the fixed core part and the housing that constitutes a part of the magnetic circuit, and distortion (internal distortion) occurs, and this distortion restricts the flow of magnetic flux. It was found that the magnetic resistance was increased.

  Therefore, based on the above knowledge, the inventors of the present invention perform a conventionally well-known annealing process of gradually cooling after heating to a predetermined temperature in order to remove internal strain due to work hardening and soften the tissue. , Succeeded in solving the above problems.

  In this case, when performing the annealing treatment, the heating temperature for recovering the magnetic properties is preferably in the range of 650 ° C. to 750 ° C. and optimally set to 700 ° C. I understood.

  As described above, in the present invention, even when the housing is integrally formed with the carbon steel material including the fixed core portion, a magnetic circuit having good magnetic characteristics can be obtained, and the magnetic attraction force is improved to improve the overall configuration. The effect that it can be reduced in size was acquired.

  In addition, the said housing is good to be integrally molded with a fixed core part by forge molding, press molding, etc., for example.

  According to the present invention, the housing includes a cylindrical portion formed with a predetermined thickness, a step portion formed continuously with the cylindrical portion and in contact with the annular flange portion, and an open end continuous with the step portion. It is comprised in the bottomed cylindrical shape which has the thin-walled cylindrical part formed in this, and the said housing and the said valve body can be simply fixed by crimping the said thin-walled cylindrical part to the said annular flange part.

  In this case, according to the present invention, the cylindrical portion of the housing is formed with a predetermined thickness, and a stepped portion and a thin cylindrical portion having a predetermined thickness along the radial direction are formed on the opening end side, The stepped portion and the thin cylindrical portion have a higher hardness than the case where the housing is formed of a carbon steel material, for example, a pure iron-based material. The thickness of the cylindrical portion in the radial direction can be reduced.

  As a result, in the present invention, the thickness of the cylindrical portion of the housing can be set thin, and the overall configuration can be further downsized by reducing the outer diameter of the housing.

  It is possible to obtain an electromagnetic actuator capable of suppressing the magnetic resistance of the housing formed integrally with the movable core portion and reducing the overall configuration.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a longitudinal sectional structure diagram along an axial direction of an electromagnetic actuator according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional structure of an on state in which a solenoid unit is energized from the off state shown in FIG. FIG.

  The electromagnetic actuator 10 includes a housing 14 in which a solenoid portion 12 is housed, and a valve body 18 that is integrally coupled to the housing 14 and in which a valve mechanism portion 16 is provided. The housing 14 and the valve body 18 function as a valve main body. The housing 14 is formed of a magnetic material made of carbon steel such as S10C (JIS standard), and the valve body 18 is, for example, , SUM (JIS standard) or other magnetic material. The carbon steel is preferably made of an alloy of iron and carbon and having a carbon content in the range of 0.02 to 2%.

  As shown in FIG. 5, the housing 14 has a bottomed cylindrical shape, and a cylindrical portion 14a formed with a predetermined thickness, and an annular flange portion 68 formed continuously from the cylindrical portion 14a and described later. It has a stepped portion 14b in contact with it, and a thin-walled cylindrical portion 14c that is continuous with the stepped portion 14b and formed at the open end. In this case, the thin cylindrical portion 14c is bent inward by a pressing portion of a caulking device (not shown) and is caulked to an annular flange portion 68 described later, whereby the housing 14 and the valve body 18 are integrally formed. It is assembled and fixed.

  The valve body 18 is formed of a substantially cylindrical body, and an inlet port 20 into which a pressure fluid (for example, pressure oil) is introduced is formed at a lower end portion of the valve body 18, and an upper side portion from the inlet port 20 is formed. Is formed with an outlet port 24 communicating with the inlet port 20 through the communication hole 22. A filter member 25 for removing dust and the like contained in the pressure oil is attached to the opening of the inlet port 20. A discharge port 28 communicating with a chamber 26 extending in the axial direction is formed inside the valve body 18 above the outlet port 24.

  In the hole 29 of the valve body 18 provided with the inlet port 20, the communication hole 22 is closed by being seated on the first seat 30, and the communication hole 22 is separated from the first seat 30. A ball 32 that functions as a valve body for opening 22 is provided. The ball 32 may be formed of bearing steel such as SUJ (JIS standard), for example. In addition, a holding guide member 35 that is formed of a resin material and holds the ball 32 by the step portion 31 and guides the ball 32 by the guide surface 33 is mounted in the hole portion 29 of the valve body 18. .

  When a coil 34 (described later) of the solenoid unit 12 is in a non-energized state, the ball 32 is separated from the first seat 30 via a valve shaft 38 pressed by a spring force of a return spring 36 described later. The valve is in an open state (see FIG. 1), and is configured as a so-called normal open type three-way electromagnetic actuator.

  A valve shaft 38 that can be displaced along the axial direction is disposed in the chamber 26 inside the valve body 18. The valve shaft 38 has a small-diameter first shaft end that has a spherical contact surface (not shown) in order from one end (the lower end in FIG. 1) upward and contacts the spherical surface of the ball 32. A portion 38a, a tapered portion 38b that is continuous with the first shaft end portion 38a and gradually increases in diameter, and a diameter-increased portion 38c that is continuous with the tapered portion 38b and press-fitted into the hole 42 of the movable core 40 described later. A small-diameter portion 38d that is continuous with the enlarged-diameter portion 38c and has a diameter smaller than that of the enlarged-diameter portion 38c; A flat notch 38e in which a space is formed between the inner wall surface of the hole 42 of the movable core 40 to be described later, and a recess 62 of the fixed core 54 to be described later that is continuous with the flat notch 38e. And a biaxial end 38f. The valve shaft 38 may be formed of a nonmagnetic material such as SUS (JIS standard).

  A partition that forms a chamber 26 is provided in an intermediate portion of the valve body 18, and a first shaft end portion 38 a of the valve shaft 38 is inserted through a central portion of the partition, and an outlet port 24 and a discharge port 28 are provided. A through hole 46 for communication is formed. A second seating portion 48 on which the tapered portion 38 b of the valve shaft 38 is seated is formed around the through hole 46.

  In addition, the outer peripheral surface of the valve body 18 is provided with first to third seal members 50a to 50c that are arranged at predetermined intervals along the axial direction and are mounted in annular grooves.

  The solenoid portion 12 has a cylindrical shape with a bottom, and is housed in the housing 14 having a fixed core portion 54 formed by a convex portion protruding by a predetermined length along the axial direction of the valve shaft 38, and the housing 14. The coil 34 is wound around the coil bobbin 56, and the movable core 40 is formed of a substantially cylindrical body and has a hole 42 that penetrates the central portion along the axial direction.

  A passage (breathing hole) 58 that is orthogonal to the axial direction and communicates with the small diameter portion 38 d of the valve shaft 38 is formed in the movable core 40. In this case, a space portion formed between the passage 58, the small diameter portion 38d of the valve shaft 38 and the inner wall of the movable core 40, and a space portion formed between the flat cutout portion 38e and the inner wall of the movable core. Are provided so as to communicate with each other, and the passage 58 has a function of releasing (circulating) the pressure fluid (pressure oil) filled in the clearance 60 between the fixed core portion 54 and the movable core 40. The coil bobbin 56 is made of, for example, a resin material.

  The fixed core portion 54 is integrally formed with the housing 14 by, for example, forging using a die (not shown), press molding, or the like. Compared to a case where a cylindrical body (not shown) formed separately from the housing is fixed to the housing to form a fixed core, in this embodiment, the fixed core portion 54 is integrally formed with the housing 14 to reduce the number of parts. This can reduce the manufacturing cost.

  Further, the solenoid portion 12 is attached to a magnet killer 35 made of a non-magnetic material having one end portion engaged with the inner wall surface of the concave portion 62 of the fixed core portion 54 and the other end portion being in contact with the end surface of the movable core 40. A return spring 36 is engaged while surrounding the second shaft end portion 38f of the valve shaft 38. When the movable core 40 is pressed in a direction away from the fixed core portion 54 by the spring force of the return spring 36 and is in an off state in which the coil 34 of the solenoid portion 12 is not energized, the movable core 40 is fixed to the movable core 40. A predetermined clearance 60 is formed between the core portion 54 (see FIG. 1). The magnet killer 35 has a function to prevent the movable core 40 from being attracted to the fixed core part 54 due to the influence of residual magnetism when the energization to the solenoid part 12 is stopped (sticking prevention function). Have

  The said movable core 40 consists of a substantially cylindrical body, for example, is formed by free-cutting steel materials, such as SUM (JIS specification). A nonmagnetic layer 64 having a predetermined depth is formed on the entire outer surface of the movable core 40 (see FIG. 3). Further, the outer peripheral surface of the end portion of the movable core 40 facing the fixed core portion 54 gradually increases in diameter as compared with other portions of the movable core 40 and has substantially the same diameter as the fixed core portion 54. An enlarged diameter portion 66 is provided.

  In this case, by forming the enlarged core portion 66 having substantially the same diameter as the fixed core portion 54 with respect to the movable core 40, the facing area of the movable core 40 to the fixed core portion 54 is increased, and the magnetic characteristics are improved. Can do.

  The nonmagnetic layer 64 of the movable core 40 is formed, for example, by applying a Kanigen plating (registered trademark) process made of electroless nickel plating. By using this Kanigen plating treatment, there is an advantage that the nonmagnetic layer 64 can be easily formed. As another method for forming the nonmagnetic layer 64 on the outer surface of the movable core 40, for example, induction hardening may be performed. When the nonmagnetic layer 64 is formed by performing induction hardening, high-speed heat treatment is possible, and the manufacturing process can be shortened.

  As shown in FIG. 4, on the upper side of the valve body 18, an annular flange portion 68 that protrudes from the outer peripheral surface in a radially outward direction by a predetermined length is provided. The upper portion starting from the annular flange portion 68 has a cylindrical inner wall surface 70 integrally formed with the annular flange portion 68 and surrounding the outer peripheral surface of the movable core 40, and has a predetermined length along the axial direction. An upper cylindrical portion 72a is provided that extends only. The lower portion starting from the annular flange portion 68 has a cylindrical inner wall surface 70 integrally formed with the annular flange portion 68 and surrounding the outer peripheral surface of the movable core 40. A lower cylindrical portion 72b extending by a predetermined length is provided.

  An end surface along the axial direction of the upper cylindrical portion 72a extends to the vicinity of the enlarged diameter portion 66 of the movable core 40 when the solenoid portion 12 shown in FIG. 1 is in an off state, and the lower cylindrical portion 72b is The solenoid portion 12 is formed to extend to a portion beyond the end surface of the movable core 40 when the solenoid portion 12 is in an off state.

  The cylindrical inner wall surfaces 70 and 70 respectively formed on the upper cylindrical portion 72a and the lower cylindrical portion 72b function as guide surfaces when the movable core 40 is slidably displaced along the axial direction. In this case, the cylindrical inner wall surface 70 of the upper cylindrical portion 72a and the cylindrical inner wall surface 70 of the lower cylindrical portion 72b are continuously formed along the axial direction, and the axial length of the guide surface is set to be large. Thus, the coaxiality with the movable core 40 can be improved.

  The thin cylindrical portion 14 c of the housing 14 is pressed by a pressing portion of a crimping device (not shown), and is crimped to the lower surface portion of the annular flange portion 68 of the valve body 18 so as to be integrally connected.

  As shown in FIG. 1, a resin sealing body 74 that molds the outer peripheral surface of the coil 34 and a part of the coil bobbin 56 is provided between the housing 14 and the coil 34. It is integrally formed of a resin material continuously with a coupler portion 76 to be described later.

  A first O-ring 78a having a triangular cross section and having a sealing function is attached to a boundary portion between the upper cylindrical portion 72a and the annular flange portion 68. A second O-ring 78b having a sealing function is mounted between the housing 14 and the coil bobbin 56.

  A coupler portion 76 that conducts to the coil 34 is provided on a side portion of the housing 14, and a terminal portion of a terminal 77 that is electrically connected to the coil 34 is provided on the coupler portion 76 so as to be exposed. . A mounting stay 80 that is bent in a substantially L shape is fixed to the side portion of the housing 14 opposite to the coupler portion 76.

  The electromagnetic actuator 10 according to the embodiment of the present invention is basically configured as described above. Next, its operation and effects will be described.

  When the coil 34 of the solenoid unit 12 is not energized, as shown in FIG. 1, the ball 32 is separated from the first seat 30 and the inlet port 20 and the outlet port 24 are in communication with each other. In addition, the tapered portion 38b of the valve shaft 38 is seated on the second seat portion 48, and the outlet port 24 and the discharge port 28 are in a non-communication state.

  Therefore, by energizing a power source (not shown) and energizing the coil 34, the solenoid unit 12 is excited and turned on, and a magnetic circuit as shown in FIG. 6 is generated. This magnetic circuit has a magnetic flux that returns to the housing 14 via the housing 14, the annular flange portion 68, the movable core 40, and the fixed core portion 54 in order.

  The movable core 40 is attracted to the fixed core portion 54 by overcoming the pressing force of the return spring 36 by the electromagnetic force generated by the magnetic circuit. At this time, the movable core 40 slides linearly by the guide action of the upper cylindrical portion 72a and the lower cylindrical portion 72b, and the valve shaft 38 integrally connected to the movable core 40 is displaced upward. To do. Accordingly, the ball 32 is seated on the first seat portion 30 by the pressing force of the pressure fluid (pressure oil) introduced from the inlet port 20, and the tapered portion 38 b of the valve shaft 38 is separated from the second seat portion 48.

  When the ball 32 is seated on the first seat portion 30 and the tapered portion 38b of the valve shaft 38 is separated from the second seat portion 48, the communication between the inlet port 20 and the outlet port 24 is blocked. At the same time, the outlet port 24 and the discharge port 28 are in communication.

  When the energization to the coil 34 of the solenoid unit 12 is stopped, the electromagnetic force disappears, and the movable core 40 and the valve shaft 38 are displaced downward under the action of the spring force of the return spring 36, and the ball 32 is pressed. Then, the ball 32 returns to the initial state in which it is separated from the first seat portion 30.

  In the present embodiment, when the housing 14 is integrally formed of a carbon steel material including the fixed core portion 54, a joint portion between the fixed core portion 54 and the housing 14 constituting a part of the magnetic circuit (FIG. 6A). (See (b)), a phenomenon occurs in which distortion occurs and the magnetic resistance increases. However, annealing is performed by gradually cooling after heating to a predetermined temperature, thereby removing the distortion and reducing the magnetoresistance. Can be suppressed.

  That is, when the solenoid part 12 is manufactured by assembling the coil 34, the movable core 40, and the like to the one in which the housing 14 is integrally formed of the carbon steel material including the fixed core part 54, the housing and the fixed core (not shown) are combined. Compared with the case where each is formed separately and assembled to the solenoid part, the minimum part for operating the solenoid part 12 (attracting the movable core 40 to the fixed core part 54 to turn on the solenoid part 12) A phenomenon occurs in which the voltage (current) increases.

  As a result of analyzing this cause by CAE (Computer Aided Engineering) analysis, stress concentrates on the joint portion (boundary portion) between the fixed core portion 54 and the housing 14 constituting a part of the magnetic circuit, and distortion (internal strain) is generated. It was found (see FIG. 7B) that the flow of magnetic flux was restricted by this distortion, and the magnetoresistance was increased.

  Therefore, based on the above knowledge, in order to remove the internal strain due to work hardening and soften the tissue, the above-mentioned problem is solved by applying a conventionally well-known annealing process that gradually cools after heating to a predetermined temperature. Succeeded.

  For example, FIG. 6 shows the easiness of the flow of magnetic flux in the coupling part of the magnetic circuit by the number of magnetic fluxes (assuming that the greater the number, the easier the magnetic flux flows), and this embodiment in which annealing treatment has been performed. Then, as shown in FIG. 6 (a), the magnetic flux easily flows along the coupling portion (boundary portion) between the fixed core portion 54 and the housing 14, whereas the comparison without annealing treatment is performed. In the example, as shown in FIG. 6 (b), the amount of magnetic flux flowing through the coupling portion is suppressed, making it difficult to distribute the magnetic flux.

  This is because, as shown in the present embodiment of FIG. 7A, the internal strain generated in the joint is softened by annealing and the crystal structure is recombined, whereas FIG. In the comparative example, since the annealing treatment is not performed, the strain consisting of the structure extending in a chain shape remains as it is in the joint portion.

  FIG. 8 shows an annealing temperature, which is a heating temperature in the annealing process, and an applied voltage at which the solenoid part 12 operates when the solenoid part 12 is configured using the housing 14 and the fixed core part 54 that have undergone the annealing process. The experimental result in a relationship is shown.

  As can be seen from FIG. 7, when the annealing treatment is performed, the applied voltage is set when the annealing temperature for restoring the magnetic properties is set within a range of 650 ° C. to 750 ° C. (points A2, A3, A4). It was found that the temperature can be set low, and it is preferable that the temperature be set to 700 ° C. In addition, as shown by the points A1 and A5, the applied voltage is unsuitable outside the range of 650 ° C. to 750 ° C.

  As described above, in this embodiment, even when the housing 14 is integrally formed with the carbon steel material including the fixed core portion 54, a magnetic circuit having good magnetic characteristics can be obtained, and the magnetic attractive force can be improved. The overall configuration can be reduced in size.

  In the present embodiment, the housing 14 has a cylindrical portion 14a formed with a predetermined thickness, a step portion 14b that is formed continuously with the cylindrical portion 14a and contacts the annular flange portion 68, and the step portion. A bottomed cylindrical shape having a thin-walled cylindrical portion 14c formed at the opening end that is continuous with the portion 14b, and the thin-walled cylindrical portion 14c is crimped to the annular flange portion 68, whereby the housing 14 and the valve The body 18 can be easily fixed.

  In this case, according to the present embodiment, the cylindrical portion 14a of the housing 14 is formed to have a predetermined thickness, and the stepped portion 14b having a predetermined thickness along the radial direction and the thin cylindrical portion are formed on the opening end side. 14c is formed, and the stepped portion 14b and the thin-walled cylindrical portion 14c have a higher hardness than the case where the housing 14 is formed of a carbon steel material, for example, compared to a case where the housing 14 is formed of a pure iron material. Therefore, the thickness in the radial direction of the stepped portion 14b and the thin cylindrical portion 14c can be reduced.

  In other words, when the housing 14 is formed of a pure iron-based material, since the magnetic characteristics are good, the size can be reduced from the viewpoint of the magnetic characteristics. Since the material hardness is low when caulking, it is unavoidable to increase the thickness of the caulking portion, and it becomes difficult to reduce the size. Further, when the housing 14 is made of a carbon steel material, since the material hardness is high, it is possible to reduce the thickness by reducing the thickness of the crimped portion, but it is necessary to increase the size because the magnetic properties are not good. Therefore, it is difficult to reduce the size. On the other hand, in the present embodiment, it is possible to achieve downsizing by satisfying both of the above two relations, that is, material hardness and magnetic characteristics.

  As a result, in the present embodiment, the thickness of the cylindrical portion 14a of the housing 14 can be set thin, and the overall configuration can be further reduced by reducing the outer diameter of the housing 14.

  In the present embodiment, since the nonmagnetic layer 64 is formed on the entire outer surface of the movable core 40 by the Kanigen plating process, the cylindrical inner wall surface 70 of the upper cylindrical portion 72a (and the lower cylindrical portion 72b) The magnetic gap formed by the clearance with the outer peripheral surface of the movable core 40 can be made as small as possible. As a result, in the present embodiment, the magnetic attraction force can be improved to further reduce the overall configuration.

  In this case, since the nonmagnetic layer 64 is formed on the entire outer surface of the movable core 40, it can be easily formed to a predetermined dimension by managing the outer diameter of only the movable core 40. Therefore, the magnetic gap can be managed with high accuracy, and extremely good magnetic characteristics can be obtained.

  Further, in the present embodiment, the valve body 18 itself is provided with a guide portion that surrounds the outer peripheral surface of the movable core 40 and guides the movable core 40 linearly along the axial direction. A separate bearing member (for example, a yoke made of an annular body) is not required, and the number of parts and the number of assembling steps can be reduced, thereby reducing the manufacturing cost.

  In this case, the guide part has a first guide part composed of an upper side cylindrical part 72a provided on the upper side starting from an annular flange part 68 projecting radially outward, and a lower side cylinder provided on the lower side. A second guide portion formed of a portion 72b, and the first guide portion and the second guide portion are continuously formed along the axial direction.

  As described above, in the present embodiment, the first guide portion and the lower-side cylindrical portion 72b each having the cylindrical inner wall surface 70 extending in the axial direction along the outer peripheral surface of the movable core 40 and including the upper-side cylindrical portion 72a. By providing the valve body 18 itself with the second guide portion, the guide surface on which the movable core 40 slides can be set long along the axial direction, and the stable guide of the movable core 40 can be set. The function can be demonstrated.

  Furthermore, since the nonmagnetic layer 64 is formed on the entire outer surface of the movable core 40, sticking to the cylindrical inner wall surface 70 is prevented, and good sliding properties of the movable core 40 with respect to the cylindrical inner wall surface 70 are prevented. Can be obtained. That is, the sliding surface (outer peripheral surface) of the movable core 40 with respect to the cylindrical inner wall surface 70 is hardened (cured) by the nonmagnetic layer 64 as compared with the magnetic layer on the inner surface thereof, so that good sliding characteristics are obtained. be able to.

It is a longitudinal cross-section structure figure along the axial direction of the electromagnetic actuator which concerns on embodiment of this invention. It is a longitudinal cross-section structure figure of the ON state by which the solenoid part was supplied with electricity from the OFF state shown by FIG. It is a longitudinal cross-sectional view along the axial direction of the movable core which comprises the said electromagnetic actuator. It is a partial expanded longitudinal cross-sectional view which shows the guide part which guides the said fixed core. FIG. 2 is a longitudinal sectional view along an axial direction of a housing in which a fixed core portion constituting the electromagnetic actuator shown in FIG. 1 is integrally formed. (A) is a partially omitted sectional view showing a magnetic circuit generated by energizing a solenoid part in this embodiment, and (b) is a partially omitted sectional view of a magnetic circuit according to a comparative example. (A) is explanatory drawing which showed the tissue state of the coupling | bond part in this embodiment, (b) is explanatory drawing which showed the tissue state of the coupling | bond part in a comparative example. It is explanatory drawing which shows the relationship between the annealing temperature in an annealing process, and the applied voltage which a solenoid part act | operates.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electromagnetic actuator 12 Solenoid part 14 Housing 14a Cylindrical part 14b Step part 14c Thin-walled cylindrical part 16 Valve mechanism part 18 Valve body 20 Inlet port 24 Outlet port 28 Outlet port 32 Ball (valve body)
34 Coil 38 Valve shaft 40 Movable core 54 Fixed core portion 68 Annular flange portion

Claims (3)

A valve body including a valve body and a housing having an inlet port and an outlet port through which pressure fluid flows; and
A coil disposed inside the housing and wound around a coil bobbin; a fixed core portion integrally formed with the housing by a carbon steel material; and a non-magnetic layer formed on an outer surface, wherein A solenoid part having a movable core sucked by the fixed core part;
A valve shaft coupled to the movable core and displaced integrally with the movable core;
A valve body that switches between a communication state and a non-communication state between the inlet port and the outlet port under the displacement action of the valve shaft;
An annular flange provided on the outer peripheral surface of the valve body and projecting radially outward;
With
The fixed core portion, the housing, the annular flange portion, and the movable core constitute a magnetic circuit,
The electromagnetic actuator according to claim 1, wherein the housing is integrally formed including the fixed core portion, and is then subjected to an annealing process of gradually cooling after being heated to a predetermined temperature. The electromagnetic actuator according to claim 1,
The housing has a bottomed cylindrical shape, a cylindrical portion formed with a predetermined thickness, a step portion formed continuously with the cylindrical portion and in contact with the annular flange portion, and an open end continuous with the step portion. An electromagnetic actuator characterized in that the housing and the valve body are fixed by crimping the thin cylindrical portion to the annular flange portion. The electromagnetic actuator according to claim 1,
The electromagnetic actuator according to claim 1, wherein the predetermined temperature heated when the annealing treatment is performed is set within a range of 650 ° C to 750 ° C.

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